Background: Jaw cysts and cyst-like lesions cause facial deformity, destruction of dental tissues and affect masticatory and phonation functions. These ad-versely erode patients’ psycho-social status;create low self-...Background: Jaw cysts and cyst-like lesions cause facial deformity, destruction of dental tissues and affect masticatory and phonation functions. These ad-versely erode patients’ psycho-social status;create low self-esteem and may change one’s facial identity and appearance. Objective: To determine the histo-pathologic characteristics, variants and demographic pattern of jaw cysts and cyst-like lesions at the University of Nairobi Dental Hospital. Material and Me-thod: This was an analytical and verification study that involved microscopic re-examination of all available incisional/excisional biopsy samples from January 2000 to December 2009 for histo-pathological diagnosis at the University of Nairobi Dental Hospital. Results: 187 jaw cysts and cyst-like lesions were diagnosed at the University of Nairobi Dental Hospital over the ten-year period. Keratocystic odontogenic tumours constituted 28%, dentigerous cysts 25%, nasopalatine duct cysts 19%, radicular cysts 15%, while calcifying odontogenic cysts comprised 4% of all the lesions. The rest of the lesions were between 1% and 3% of all the lesion entities. Conclusion: Keratocystic odontogenic tumours and dentigerous cysts were the most common developmental odontogenic cysts diagnosed in the ten-year period.展开更多
Biocompatibility of dental porcelain is of crucial importance to the long-term success of dental prostheses because of its close contact with oral tissues for extended periods. This investigation was aimed to evaluate...Biocompatibility of dental porcelain is of crucial importance to the long-term success of dental prostheses because of its close contact with oral tissues for extended periods. This investigation was aimed to evaluate cellular responses to locally produced dental porcelain （Universiti Sains Malaysia, Malaysia） after a short-term subcutaneous implantation in a rat model. Locally produced dental porcelains supplied in disc form were implanted subcutaneously into 12 Sprague-Dawley male albino rats, which were sacrificed in groups of 3 at 1, 2, 3 and 4 weeks after implantation. A semi-quantitative histological analysis of the tissue surrounding implanted discs was done under an image analyzer after staining with hematoxyline and eosin. The macrophage was clearly the dominant cell type at the implant surface at the first week after implantation, followed by a gradual decrease as the implantation period increased. On the contrary, fibroblasts and fibrocytes were the dominant cell types in the tissue surrounding the implanted discs at the third and fourth week after implantation with the appearance of mature collagen. From pathological point of view, the disappearance of inflammatory cellular responses and the well matured fibrous connective tissue surrounding the implanted discs indicate a satisfactory in vivo biocompatibility.展开更多
The objective of the study was to describe the prevalence and severity of gingival overgrowth (GO) among patients on anti-hypertensive pharmacotherapy at a Nairobi hospital in Kenya and to evaluate the relationship be...The objective of the study was to describe the prevalence and severity of gingival overgrowth (GO) among patients on anti-hypertensive pharmacotherapy at a Nairobi hospital in Kenya and to evaluate the relationship between GO and associated risk factors among these patients. The study design was a cross-sectional survey using a consecutive convenient sampling method. All the patients were examined for gingival enlargement by the method described by Seymour, et al. and modified by the authors to allow for measurement in millimetres. Gingival inflammatory status and plaque scores were also evaluated. The results showed that of the 164 hypertensive patients recruited, 20.7% had gingival overgrowth. Slightly over half (56.1%) of these patients were on calcium channel blockers (CCB). Patients on CCB had a higher prevalence (31.5%) of GO compared to those on non-CCB (7%). This difference was statistically significant (Yates χ2 = 13.39: 1 df: P = 0.000) with an odds ratio of 6.17 (95% CI 0.21 - 19.45). There was no statistically significant association between gender, drug dosage, plaque levels and gingivitis with GO. In conclusion, usage of CCB pharmacotherapy showed a significant association with GO.展开更多
The position and branching of the lingual nerve (LN) in the mandibular third molar region were documented in 30 head hemi-sections (16: right and 14: left). In all the dissections, the LN was found below the level of ...The position and branching of the lingual nerve (LN) in the mandibular third molar region were documented in 30 head hemi-sections (16: right and 14: left). In all the dissections, the LN was found below the level of the posterior alveolar crest (PAC). Branching was observed in 26 (86.7%) of the 30 specimen in which one branch was most frequently given per hemi-section. All branches were located superior to the main trunk of the LN. The mean vertical distance of the LN from the PAC was 10.3 ± 5.2 mm (range: 2.8 - 19.9 mm) whereas the mean antero-posterior distance was 7.1 ± 2.8 mm (range: 1.3 - 15.6 mm). The mean mandibular height from the PAC was 28.7 ± 4.0 mm (range: 23.3 - 40.7 mm). The vertical distance and mandibular height correlated positively giving a ratio of 1:2.7 between the two parameters. There was no significant difference between the two sides of the head. Position of the LN differed from previous studies suggesting that ethnicity may have a role in morphometry of the nerve. Use of different methodology may also contribute to this. Branches of the LN being closer to the PAC may be more prone to injury than the main trunk during surgical treatment.展开更多
Objective: To evaluate the in vitro antimicrobial effectiveness of commercial herbal-based mouthrinses against oral microorganisms. Methods: A total of three mouthrinses(OX, Pesona and Watsons) were tested for their a...Objective: To evaluate the in vitro antimicrobial effectiveness of commercial herbal-based mouthrinses against oral microorganisms. Methods: A total of three mouthrinses(OX, Pesona and Watsons) were tested for their antimicrobial activity against six oral organisms, Streptococcus mutans(S. mutans), Streptococcus sobrinus(S. sobrinus), Lactobacillus salivarius(L. salivarius), Staphylococcus aureus(S. aureus), Pseudomonas aeruginosa(P. aeruginosa) and Candida albicans(C. albicans) by standard agar-disk diffusion assay. Oradex mouthrinse containing 0.12% chlorhexidine gluconate and sterile distilled water was served as positive and negative controls, respectively. Results: All mouthrinse formulations were effective in inhibiting the growth of S. mutans, S. sobrinus, L. salivarius and C. albicans. Among the tested mouthrinses, Pesona was the only effective mouthrinse against S. aureus and P. aeruginosa, similar to Oradex mouthrinse. Pesona mouthrinse formulation appears to be as effective as Oradex mouthrinse formulation to kill S. aureus and P. aeruginosa. Statistical analysis showed no significant difference among the tested formulations regarding their antimicrobial activities(P > 0.05).Conclusions: Pesona was not the only herbal mouthrinse effective in inhibiting the growth of S. mutans, S. sobrinus, L. salivarius and C. albicans in vitro. All tested formulations were effective against those strains. Our findings may serve as a guide for selecting a kind of herbal mouthrinses as well as providing information to the dental professionals about the efficacy of these products.展开更多
Objective:To produce a technique for the growth of Campylobacter jejuni in aerobic condition Methods:Different combinations of reducing agents were tested in brucella broth and the growth turbidity was compared with t...Objective:To produce a technique for the growth of Campylobacter jejuni in aerobic condition Methods:Different combinations of reducing agents were tested in brucella broth and the growth turbidity was compared with tubes containing normal broth only.Microaerophilic environment was also provided in a petri plate seeded with Campylobacter culture by pouring 3 different concentrations（10%,5%and 2.5%） of five reducing agents along with bacto-agar in the lid which was used to cover and seal the culture plate.Six reducing agents were also added in broth in concentration of 0.25 mg/mL of each with different combinations.Results:In lid agar technique,Campylobacter jejuni growth appeared in all three concentrations of reducing agents, that is 10%,5%and 2.5%after 24 hours of incubation but the best results were observed in 10% concentration.The colonial and morphological characters were not affected when the organisms were grown by this technique.Conclusions:It was found that reducing agents enhance the growth of C.jejuni/coli.In combination of FeSO<sub>4</sub>,Na<sub>2</sub>CO<sub>3</sub> with H<sub>3</sub>BO<sub>3</sub> worked as ideal mixture for the aerobic growth of Campylobacter.This technique is more economical as compared to commercially available media in the market and can be used for the oral facultative and microaerophilic bacterial growth in laboratory.展开更多
Objective:To analyze the effect of selected plant product against several bacterial which commonly causes oral infection.It was hope that in future,this product will become the remedy for treatment of oral infection a...Objective:To analyze the effect of selected plant product against several bacterial which commonly causes oral infection.It was hope that in future,this product will become the remedy for treatment of oral infection and with the hope that it can substitute antibiotics.Methods:A total of 5 species of oral bacteria from American Type Culture Collection(ATCC) were employed in this study(S.mutans,S.aureus,P.aeruginosa,S.sobrinus and L.salivarius ).Three types of natural plants crude extracts were used(garlic,curry leaves and cloves).Bactericidal and bacteriostatic effects of these herbs were tested.Results:It was shown garlic had antibacterial effects on all bacteria.The Minimal Inhibitory Concentration(MIC in g/mL) of garlic towards S. aureus,P.aeruginosa,S.mutans,S.sobrinus and L.salivarius were 0.3,1.8,1.2,0.5 and 1.8,respectively. There was significant difference among the MIC of garlic on tested bacteria.It was more potent toward S.aureus. The curry leaf solution on the other hand,did not show any zone of inhibition in all bacteria plates but adversely showed enhanced growth of those bacteria.Clove had shown its antibacterial effects on 5.aureus and P.aeruginosa.The clove was more potent toward S.aureus with the MIC of 0.45 g/mL.P.aeruginosa was more sensitive to clove compared to garlic.For 5.aureus,it was more sensitive to garlic compared to clove. Conclusion:The antibacterial activity of garlic and clove crude extracts shown in our study further confirm these natural plants’potential usage in therapeutic use for oral diseases or infections.This could be the platform for the interested party to do research and development on it and to produce oral health products which are more affordable for lower economic income groups and with fewer side effects as seen in synthetic drug.展开更多
Objective: To identify the phytochemical compounds from Annona muricata(A. muricata) and to determine their in vitro anti-proliferative activities against breast cancer cells, MCF7 and MDA-MB-231. Methods: A. muricata...Objective: To identify the phytochemical compounds from Annona muricata(A. muricata) and to determine their in vitro anti-proliferative activities against breast cancer cells, MCF7 and MDA-MB-231. Methods: A. muricata leaves were successively extracted by soxhlet method using n-hexane, ethyl acetate and methanol, and decocted with water. Each extract was analysed by gas chromatography mass spectrometry(GCMS) and characterized with Wiley and NIST library searches. Anti-proliferative activity of each extract was evaluated on MCF7 and MDA-MB-231 breast cancer cells using MTT assay. Results: The GCMS analysis of different solvent extracts of A. muricata leaves showed presence of different chemical groups of compounds such as steroids, terpenoids, phenolic compounds, sugars, sugars alcohol and others including vitamin E. Ethyl acetate leaves extract exhibited the lowest IC_(50) value on the MDA-MB-231 breast cancer cell and n-hexane leaves extract showed the the lowest IC_(50) value on the MCF-7 breast cancer cell. Conclusion: Steroids and phenolic compounds were the main phytocompound groups identified from all A. muricata leaves extracts. The antiproliferative activity of n-hexane and ethyl acetate extract towards breast cancer MCF7 and MDA-MB-231 respectively might be due to the presence of biologically active compounds in the extracts, hence, providing some scientific evidences of the effectiveness of its traditional usages.展开更多
A qualitative and quantitative workplace assessment was carried out to determine naphtha exposure in a tyre manufacturing industry. A qualitative chemical health risk assessment was conducted to identify naphtha hazar...A qualitative and quantitative workplace assessment was carried out to determine naphtha exposure in a tyre manufacturing industry. A qualitative chemical health risk assessment was conducted to identify naphtha hazard at the workplace. Quantitative assessment using Portable VOC Monitor, Automatic Sampling Pump and personal air sampling pump was used to determine VOC concentrations, organic solvents, and individual air naphtha respectively. The risk rating of naphtha was estimated to be 5. The mean VOC concentration was in the range of 2.43 to 92.93 ppm. Repair area had the highest VOC concentration while the lowest was in the moulding area. Each work station had significant differences for VOC concentrations （p 〈 0.001）. Laboratory analysis found various solvents including 2-methyl pentane, hexane, methyl cyclopentane, heptane, cyclohexane and toluene which were present in the liquid naphtha. Only xylene has been detected in the making and moulding areas with a range of 2 to 5 ppm. Meanwhile, the air naphtha concentrations of the exposed workers were significantly higher than those unexposed. The risk of naphtha exposure was qualitatively significant and not adequately controlled. Naphtha was detected in all work stations since it is the main solvent used. The ＂Repair Area＂ was significantly more contaminated than the other area.展开更多
Antibacterial activity of zinc oxide nanoparticles(Zn O-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many micro...Antibacterial activity of zinc oxide nanoparticles(Zn O-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many microorganisms exist in the range from hundreds of nanometers to tens of micrometers. Zn O-NPs exhibit attractive antibacterial properties due to increased specific surface area as the reduced particle size leading to enhanced particle surface reactivity. Zn O is a bio-safe material that possesses photo-oxidizing and photocatalysis impacts on chemical and biological species. This review covered Zn O-NPs antibacterial activity including testing methods, impact of UV illumination, Zn O particle properties(size, concentration, morphology, and defects), particle surface modification, and minimum inhibitory concentration. Particular emphasize was given to bactericidal and bacteriostatic mechanisms with focus on generation of reactive oxygen species(ROS) including hydrogen peroxide(H2O2), OH-(hydroxyl radicals), and O2-2(peroxide). ROS has been a major factor for several mechanisms including cell wall damage due to Zn O-localized interaction, enhanced membrane permeability, internalization of NPs due to loss of proton motive force and uptake of toxic dissolved zinc ions.These have led to mitochondria weakness, intracellular outflow, and release in gene expression of oxidative stress which caused eventual cell growth inhibition and cell death. In some cases, enhanced antibacterial activity can be attributed to surface defects on Zn O abrasive surface texture. One functional application of the Zn O antibacterial bioactivity was discussed in food packaging industry where Zn O-NPs are used as an antibacterial agent toward foodborne diseases. Proper incorporation of Zn O-NPs into packaging materials can cause interaction with foodborne pathogens, thereby releasing NPs onto food surface where they come in contact with bad bacteria and cause the bacterial death and/or inhibition.展开更多
Objective: To determine the clinico-histopathologic variations and etiological factors associated with oral squamous cell carcinoma (OSCC). Methods: A descriptive cross-sectional hospital based study was conducted at ...Objective: To determine the clinico-histopathologic variations and etiological factors associated with oral squamous cell carcinoma (OSCC). Methods: A descriptive cross-sectional hospital based study was conducted at the University of Nairobi Dental Hospital (UNDH) and Kenyatta National Hospital (KNH) between September 2008 and February 2009. Eighty-two (82) patients presenting with lesions confirmed as OSCC were evaluated for habits identified as risk factors such as tobacco use, alcohol use and betel quid chewing. Demographic features including age and gender as well as clinical parameters such as site of the primary lesion, tumour size and nodal involvement were documented. Incisional biopsies were performed for all patients to confirm the diagnosis and histopathological features noted. Results: The mean age of the patients was 58.49 (range = 14 to 90 years), with a male to female ratio of 1.6:1. Remarkably, 13.4% of the patients were aged 40 years and below. The peak incidence was found to have been in the 6th - 7th decades. Tobacco use was the main associated etiological factor (73.2%) followed by alcohol use (57.3%). Notably, 25.6% of the cases had no identifiable risk factor. The tongue was the most common site (35%) followed by the palate (22%) (p = 0.03). The least commonly affected site was the floor of the mouth (10%). The most common stage at presentation was stage IV (52.4%) and;the poorly differentiated OSCC was the most common histopathologic variant (48.8%) followed by the well differentiated (30.5%) and moderately differentiated OSCC (20.7%). Conclusion: In the present investigation it is evident that OSCC has a male predilection with a peak incidence in the 6th - 7th decades and most commonly manifests in the tongue at stage IV with the poorly differentiated subtype being the most common. Of the cases diagnosed 13.4% were aged 40 years and below.展开更多
Worldwide there has been a significant increase in the incidence of oropharyngeal squamous cell carcinoma(OPSCC)etiologically attributed to oncogenic human papillomavirus(HPV).Reliable and accurate identification and ...Worldwide there has been a significant increase in the incidence of oropharyngeal squamous cell carcinoma(OPSCC)etiologically attributed to oncogenic human papillomavirus(HPV).Reliable and accurate identification and detection tools are important as the incidence of HPV-related cancer is on the rise.Several HPV detection methods for OPSCC have been developed and each has its own advantages and disadvantages in regard to sensitivity,specificity,and technical difficulty.This review summarizes our current knowledge of molecular methods for detecting HPV in OPSCC,including HPV DNA/RNA polymerase chain reaction(PCR),loop-mediated isothermal amplification(LAMP),p16 immunohistochemistry(IHC),and DNA/RNA in situ hybridization(ISH)assays.This summary may facilitate the selection of a suitable method for detecting HPV infection,and therefore may help in the early diagnosis of HPV-related carcinoma to reduce its mortality,incidence,and morbidity.展开更多
Bacterial attachment is a complex process affected by flow conditions,imparted stresses,and the surface properties and structure of both the supporting material and the cell.Experiments on the initial attachment of ce...Bacterial attachment is a complex process affected by flow conditions,imparted stresses,and the surface properties and structure of both the supporting material and the cell.Experiments on the initial attachment of cells of the bacterium Streptococcus gordonii(S.gordonii),an important early coloniser of dental plaque,to samples of stainless steel(SS)have been reported in this work.The primary aim motivating this study was to establish what affect,if any,the surface roughness and topology of samples of SS would have on the initial attachment of cells of the bacterium S.gordonii.This material and bacterium were chosen by virtue of their relevance to dental implants and dental implant infections.Prior to bacterial attachment,surfaces become conditioned by the interfacing environment(salivary pellicle from the oral cavity for instance).For this reason,cell attachment to samples of SS pre-coated with saliva was also studied.By implementing the Extended Derjaguin Landau Verwey and Overbeek(XDLVO)theory coupled with convection-diffusion-reaction equations and the surface roughness information,a computational model was developed to help better understand the physics of cell adhesion.Surface roughness was modelled by reconstructing the surface topography using statistical parameters derived from atomic force microscopy(AFM)measurements.Using this computational model,the effects of roughness and surface patterns on bacterial attachment were examined quantitatively in both static and flowing fluid environments.The results have shown that rougher surfaces(within the sub-microscale)generally increase bacterial attachment in static fluid conditions which quantitatively agrees with experimental measurements.Under flow conditions,computational fluid dynamics(CFD)simulations predicted reduced convection-diffusion inside the channel which would act to decrease bacterial attachment.When combined with surface roughness effects,the computational model also predicted that the surface topographies discussed within this work produced a slight decrease in overall bacterial attachment.This would suggest that the attachment-preventing effects of surface patterns dominate over the adhesion-favourable sub-microscale surface roughness;hence,producing a net reduction in adhered cells.This qualitatively agreed with experimental observations reported here and quantitatively matched experimental observations for low flow rates within measurement error.展开更多
文摘Background: Jaw cysts and cyst-like lesions cause facial deformity, destruction of dental tissues and affect masticatory and phonation functions. These ad-versely erode patients’ psycho-social status;create low self-esteem and may change one’s facial identity and appearance. Objective: To determine the histo-pathologic characteristics, variants and demographic pattern of jaw cysts and cyst-like lesions at the University of Nairobi Dental Hospital. Material and Me-thod: This was an analytical and verification study that involved microscopic re-examination of all available incisional/excisional biopsy samples from January 2000 to December 2009 for histo-pathological diagnosis at the University of Nairobi Dental Hospital. Results: 187 jaw cysts and cyst-like lesions were diagnosed at the University of Nairobi Dental Hospital over the ten-year period. Keratocystic odontogenic tumours constituted 28%, dentigerous cysts 25%, nasopalatine duct cysts 19%, radicular cysts 15%, while calcifying odontogenic cysts comprised 4% of all the lesions. The rest of the lesions were between 1% and 3% of all the lesion entities. Conclusion: Keratocystic odontogenic tumours and dentigerous cysts were the most common developmental odontogenic cysts diagnosed in the ten-year period.
文摘Biocompatibility of dental porcelain is of crucial importance to the long-term success of dental prostheses because of its close contact with oral tissues for extended periods. This investigation was aimed to evaluate cellular responses to locally produced dental porcelain （Universiti Sains Malaysia, Malaysia） after a short-term subcutaneous implantation in a rat model. Locally produced dental porcelains supplied in disc form were implanted subcutaneously into 12 Sprague-Dawley male albino rats, which were sacrificed in groups of 3 at 1, 2, 3 and 4 weeks after implantation. A semi-quantitative histological analysis of the tissue surrounding implanted discs was done under an image analyzer after staining with hematoxyline and eosin. The macrophage was clearly the dominant cell type at the implant surface at the first week after implantation, followed by a gradual decrease as the implantation period increased. On the contrary, fibroblasts and fibrocytes were the dominant cell types in the tissue surrounding the implanted discs at the third and fourth week after implantation with the appearance of mature collagen. From pathological point of view, the disappearance of inflammatory cellular responses and the well matured fibrous connective tissue surrounding the implanted discs indicate a satisfactory in vivo biocompatibility.
文摘The objective of the study was to describe the prevalence and severity of gingival overgrowth (GO) among patients on anti-hypertensive pharmacotherapy at a Nairobi hospital in Kenya and to evaluate the relationship between GO and associated risk factors among these patients. The study design was a cross-sectional survey using a consecutive convenient sampling method. All the patients were examined for gingival enlargement by the method described by Seymour, et al. and modified by the authors to allow for measurement in millimetres. Gingival inflammatory status and plaque scores were also evaluated. The results showed that of the 164 hypertensive patients recruited, 20.7% had gingival overgrowth. Slightly over half (56.1%) of these patients were on calcium channel blockers (CCB). Patients on CCB had a higher prevalence (31.5%) of GO compared to those on non-CCB (7%). This difference was statistically significant (Yates χ2 = 13.39: 1 df: P = 0.000) with an odds ratio of 6.17 (95% CI 0.21 - 19.45). There was no statistically significant association between gender, drug dosage, plaque levels and gingivitis with GO. In conclusion, usage of CCB pharmacotherapy showed a significant association with GO.
文摘The position and branching of the lingual nerve (LN) in the mandibular third molar region were documented in 30 head hemi-sections (16: right and 14: left). In all the dissections, the LN was found below the level of the posterior alveolar crest (PAC). Branching was observed in 26 (86.7%) of the 30 specimen in which one branch was most frequently given per hemi-section. All branches were located superior to the main trunk of the LN. The mean vertical distance of the LN from the PAC was 10.3 ± 5.2 mm (range: 2.8 - 19.9 mm) whereas the mean antero-posterior distance was 7.1 ± 2.8 mm (range: 1.3 - 15.6 mm). The mean mandibular height from the PAC was 28.7 ± 4.0 mm (range: 23.3 - 40.7 mm). The vertical distance and mandibular height correlated positively giving a ratio of 1:2.7 between the two parameters. There was no significant difference between the two sides of the head. Position of the LN differed from previous studies suggesting that ethnicity may have a role in morphometry of the nerve. Use of different methodology may also contribute to this. Branches of the LN being closer to the PAC may be more prone to injury than the main trunk during surgical treatment.
基金supported by the Incentive Grant Universiti Sains Malaysia,Malaysia
文摘Objective: To evaluate the in vitro antimicrobial effectiveness of commercial herbal-based mouthrinses against oral microorganisms. Methods: A total of three mouthrinses(OX, Pesona and Watsons) were tested for their antimicrobial activity against six oral organisms, Streptococcus mutans(S. mutans), Streptococcus sobrinus(S. sobrinus), Lactobacillus salivarius(L. salivarius), Staphylococcus aureus(S. aureus), Pseudomonas aeruginosa(P. aeruginosa) and Candida albicans(C. albicans) by standard agar-disk diffusion assay. Oradex mouthrinse containing 0.12% chlorhexidine gluconate and sterile distilled water was served as positive and negative controls, respectively. Results: All mouthrinse formulations were effective in inhibiting the growth of S. mutans, S. sobrinus, L. salivarius and C. albicans. Among the tested mouthrinses, Pesona was the only effective mouthrinse against S. aureus and P. aeruginosa, similar to Oradex mouthrinse. Pesona mouthrinse formulation appears to be as effective as Oradex mouthrinse formulation to kill S. aureus and P. aeruginosa. Statistical analysis showed no significant difference among the tested formulations regarding their antimicrobial activities(P > 0.05).Conclusions: Pesona was not the only herbal mouthrinse effective in inhibiting the growth of S. mutans, S. sobrinus, L. salivarius and C. albicans in vitro. All tested formulations were effective against those strains. Our findings may serve as a guide for selecting a kind of herbal mouthrinses as well as providing information to the dental professionals about the efficacy of these products.
文摘Objective:To produce a technique for the growth of Campylobacter jejuni in aerobic condition Methods:Different combinations of reducing agents were tested in brucella broth and the growth turbidity was compared with tubes containing normal broth only.Microaerophilic environment was also provided in a petri plate seeded with Campylobacter culture by pouring 3 different concentrations（10%,5%and 2.5%） of five reducing agents along with bacto-agar in the lid which was used to cover and seal the culture plate.Six reducing agents were also added in broth in concentration of 0.25 mg/mL of each with different combinations.Results:In lid agar technique,Campylobacter jejuni growth appeared in all three concentrations of reducing agents, that is 10%,5%and 2.5%after 24 hours of incubation but the best results were observed in 10% concentration.The colonial and morphological characters were not affected when the organisms were grown by this technique.Conclusions:It was found that reducing agents enhance the growth of C.jejuni/coli.In combination of FeSO<sub>4</sub>,Na<sub>2</sub>CO<sub>3</sub> with H<sub>3</sub>BO<sub>3</sub> worked as ideal mixture for the aerobic growth of Campylobacter.This technique is more economical as compared to commercially available media in the market and can be used for the oral facultative and microaerophilic bacterial growth in laboratory.
文摘Objective:To analyze the effect of selected plant product against several bacterial which commonly causes oral infection.It was hope that in future,this product will become the remedy for treatment of oral infection and with the hope that it can substitute antibiotics.Methods:A total of 5 species of oral bacteria from American Type Culture Collection(ATCC) were employed in this study(S.mutans,S.aureus,P.aeruginosa,S.sobrinus and L.salivarius ).Three types of natural plants crude extracts were used(garlic,curry leaves and cloves).Bactericidal and bacteriostatic effects of these herbs were tested.Results:It was shown garlic had antibacterial effects on all bacteria.The Minimal Inhibitory Concentration(MIC in g/mL) of garlic towards S. aureus,P.aeruginosa,S.mutans,S.sobrinus and L.salivarius were 0.3,1.8,1.2,0.5 and 1.8,respectively. There was significant difference among the MIC of garlic on tested bacteria.It was more potent toward S.aureus. The curry leaf solution on the other hand,did not show any zone of inhibition in all bacteria plates but adversely showed enhanced growth of those bacteria.Clove had shown its antibacterial effects on 5.aureus and P.aeruginosa.The clove was more potent toward S.aureus with the MIC of 0.45 g/mL.P.aeruginosa was more sensitive to clove compared to garlic.For 5.aureus,it was more sensitive to garlic compared to clove. Conclusion:The antibacterial activity of garlic and clove crude extracts shown in our study further confirm these natural plants’potential usage in therapeutic use for oral diseases or infections.This could be the platform for the interested party to do research and development on it and to produce oral health products which are more affordable for lower economic income groups and with fewer side effects as seen in synthetic drug.
基金funded by the Universiti Sains Malaysia Short Term Grant(304/PPSP/6313322)
文摘Objective: To identify the phytochemical compounds from Annona muricata(A. muricata) and to determine their in vitro anti-proliferative activities against breast cancer cells, MCF7 and MDA-MB-231. Methods: A. muricata leaves were successively extracted by soxhlet method using n-hexane, ethyl acetate and methanol, and decocted with water. Each extract was analysed by gas chromatography mass spectrometry(GCMS) and characterized with Wiley and NIST library searches. Anti-proliferative activity of each extract was evaluated on MCF7 and MDA-MB-231 breast cancer cells using MTT assay. Results: The GCMS analysis of different solvent extracts of A. muricata leaves showed presence of different chemical groups of compounds such as steroids, terpenoids, phenolic compounds, sugars, sugars alcohol and others including vitamin E. Ethyl acetate leaves extract exhibited the lowest IC_(50) value on the MDA-MB-231 breast cancer cell and n-hexane leaves extract showed the the lowest IC_(50) value on the MCF-7 breast cancer cell. Conclusion: Steroids and phenolic compounds were the main phytocompound groups identified from all A. muricata leaves extracts. The antiproliferative activity of n-hexane and ethyl acetate extract towards breast cancer MCF7 and MDA-MB-231 respectively might be due to the presence of biologically active compounds in the extracts, hence, providing some scientific evidences of the effectiveness of its traditional usages.
文摘A qualitative and quantitative workplace assessment was carried out to determine naphtha exposure in a tyre manufacturing industry. A qualitative chemical health risk assessment was conducted to identify naphtha hazard at the workplace. Quantitative assessment using Portable VOC Monitor, Automatic Sampling Pump and personal air sampling pump was used to determine VOC concentrations, organic solvents, and individual air naphtha respectively. The risk rating of naphtha was estimated to be 5. The mean VOC concentration was in the range of 2.43 to 92.93 ppm. Repair area had the highest VOC concentration while the lowest was in the moulding area. Each work station had significant differences for VOC concentrations （p 〈 0.001）. Laboratory analysis found various solvents including 2-methyl pentane, hexane, methyl cyclopentane, heptane, cyclohexane and toluene which were present in the liquid naphtha. Only xylene has been detected in the making and moulding areas with a range of 2 to 5 ppm. Meanwhile, the air naphtha concentrations of the exposed workers were significantly higher than those unexposed. The risk of naphtha exposure was qualitatively significant and not adequately controlled. Naphtha was detected in all work stations since it is the main solvent used. The ＂Repair Area＂ was significantly more contaminated than the other area.
基金support from a research university Grant number 1001/PFIZIK/814174 of Universiti Sains Malaysia(USM)
文摘Antibacterial activity of zinc oxide nanoparticles(Zn O-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many microorganisms exist in the range from hundreds of nanometers to tens of micrometers. Zn O-NPs exhibit attractive antibacterial properties due to increased specific surface area as the reduced particle size leading to enhanced particle surface reactivity. Zn O is a bio-safe material that possesses photo-oxidizing and photocatalysis impacts on chemical and biological species. This review covered Zn O-NPs antibacterial activity including testing methods, impact of UV illumination, Zn O particle properties(size, concentration, morphology, and defects), particle surface modification, and minimum inhibitory concentration. Particular emphasize was given to bactericidal and bacteriostatic mechanisms with focus on generation of reactive oxygen species(ROS) including hydrogen peroxide(H2O2), OH-(hydroxyl radicals), and O2-2(peroxide). ROS has been a major factor for several mechanisms including cell wall damage due to Zn O-localized interaction, enhanced membrane permeability, internalization of NPs due to loss of proton motive force and uptake of toxic dissolved zinc ions.These have led to mitochondria weakness, intracellular outflow, and release in gene expression of oxidative stress which caused eventual cell growth inhibition and cell death. In some cases, enhanced antibacterial activity can be attributed to surface defects on Zn O abrasive surface texture. One functional application of the Zn O antibacterial bioactivity was discussed in food packaging industry where Zn O-NPs are used as an antibacterial agent toward foodborne diseases. Proper incorporation of Zn O-NPs into packaging materials can cause interaction with foodborne pathogens, thereby releasing NPs onto food surface where they come in contact with bad bacteria and cause the bacterial death and/or inhibition.
文摘Objective: To determine the clinico-histopathologic variations and etiological factors associated with oral squamous cell carcinoma (OSCC). Methods: A descriptive cross-sectional hospital based study was conducted at the University of Nairobi Dental Hospital (UNDH) and Kenyatta National Hospital (KNH) between September 2008 and February 2009. Eighty-two (82) patients presenting with lesions confirmed as OSCC were evaluated for habits identified as risk factors such as tobacco use, alcohol use and betel quid chewing. Demographic features including age and gender as well as clinical parameters such as site of the primary lesion, tumour size and nodal involvement were documented. Incisional biopsies were performed for all patients to confirm the diagnosis and histopathological features noted. Results: The mean age of the patients was 58.49 (range = 14 to 90 years), with a male to female ratio of 1.6:1. Remarkably, 13.4% of the patients were aged 40 years and below. The peak incidence was found to have been in the 6th - 7th decades. Tobacco use was the main associated etiological factor (73.2%) followed by alcohol use (57.3%). Notably, 25.6% of the cases had no identifiable risk factor. The tongue was the most common site (35%) followed by the palate (22%) (p = 0.03). The least commonly affected site was the floor of the mouth (10%). The most common stage at presentation was stage IV (52.4%) and;the poorly differentiated OSCC was the most common histopathologic variant (48.8%) followed by the well differentiated (30.5%) and moderately differentiated OSCC (20.7%). Conclusion: In the present investigation it is evident that OSCC has a male predilection with a peak incidence in the 6th - 7th decades and most commonly manifests in the tongue at stage IV with the poorly differentiated subtype being the most common. Of the cases diagnosed 13.4% were aged 40 years and below.
基金Project supported by the Universiti Sains Malaysia Research University Grant(1001/PPSG/8012345)。
文摘Worldwide there has been a significant increase in the incidence of oropharyngeal squamous cell carcinoma(OPSCC)etiologically attributed to oncogenic human papillomavirus(HPV).Reliable and accurate identification and detection tools are important as the incidence of HPV-related cancer is on the rise.Several HPV detection methods for OPSCC have been developed and each has its own advantages and disadvantages in regard to sensitivity,specificity,and technical difficulty.This review summarizes our current knowledge of molecular methods for detecting HPV in OPSCC,including HPV DNA/RNA polymerase chain reaction(PCR),loop-mediated isothermal amplification(LAMP),p16 immunohistochemistry(IHC),and DNA/RNA in situ hybridization(ISH)assays.This summary may facilitate the selection of a suitable method for detecting HPV infection,and therefore may help in the early diagnosis of HPV-related carcinoma to reduce its mortality,incidence,and morbidity.
基金Subash Bommu Chinnaraj acknowledges the Newcastle University SAGE DTA studentshipEPSRC DTP scholarshipfunding from the Engineering and Physical Sciences Research Council(No.EP/K039083/1)。
文摘Bacterial attachment is a complex process affected by flow conditions,imparted stresses,and the surface properties and structure of both the supporting material and the cell.Experiments on the initial attachment of cells of the bacterium Streptococcus gordonii(S.gordonii),an important early coloniser of dental plaque,to samples of stainless steel(SS)have been reported in this work.The primary aim motivating this study was to establish what affect,if any,the surface roughness and topology of samples of SS would have on the initial attachment of cells of the bacterium S.gordonii.This material and bacterium were chosen by virtue of their relevance to dental implants and dental implant infections.Prior to bacterial attachment,surfaces become conditioned by the interfacing environment(salivary pellicle from the oral cavity for instance).For this reason,cell attachment to samples of SS pre-coated with saliva was also studied.By implementing the Extended Derjaguin Landau Verwey and Overbeek(XDLVO)theory coupled with convection-diffusion-reaction equations and the surface roughness information,a computational model was developed to help better understand the physics of cell adhesion.Surface roughness was modelled by reconstructing the surface topography using statistical parameters derived from atomic force microscopy(AFM)measurements.Using this computational model,the effects of roughness and surface patterns on bacterial attachment were examined quantitatively in both static and flowing fluid environments.The results have shown that rougher surfaces(within the sub-microscale)generally increase bacterial attachment in static fluid conditions which quantitatively agrees with experimental measurements.Under flow conditions,computational fluid dynamics(CFD)simulations predicted reduced convection-diffusion inside the channel which would act to decrease bacterial attachment.When combined with surface roughness effects,the computational model also predicted that the surface topographies discussed within this work produced a slight decrease in overall bacterial attachment.This would suggest that the attachment-preventing effects of surface patterns dominate over the adhesion-favourable sub-microscale surface roughness;hence,producing a net reduction in adhered cells.This qualitatively agreed with experimental observations reported here and quantitatively matched experimental observations for low flow rates within measurement error.
